Characterization of as-deposited Li_4Ti_5O_(12) thin film electrode prepared by aerosol deposition method

摘要

We successfully fabricated lithium titanate Li_4Ti_5O_(12) (LTO) thin film electrode at room temperature by aerosol deposition (AD) method. Agglomerated LTO powder with the size of 5-6 μm composed of primary sub-micron particles was used as raw material and deposited directly on a stainless steel substrate via room temperature impact consolidation (RTIC). X-ray diffraction patterns revealed that as-deposited LTO film has a same crystalline structure with raw powder and no secondary phases were formed during the deposition process. SEM observation showed that the film has porous structure consisted from LTO particles with the sizes of several 100 nm. As-deposited LTO film electrode showed good electrochemical property in liquid electrolyte. The discharge capacities of 159 mAh g~(-1) and 125 mAh g~(-1) were obtained at current density of 0.067 mA cm~(-2) (=0.5C rate) and 2.68 mA cm~(-2) (=20C rate). The former corresponds to 91% of theoretical capacity for LTO ( = 175 mAh g~(-1)). The film electrode also showed good capacity retention, indicating that adhesion between the film and substrate are sufficiently strong.